1. Field of the Invention
The present invention relates to a toner container and an image forming apparatus including the toner container.
2. Description of the Related Art
In a conventional image forming apparatus using the electrophotographic system, a cylindrical toner container for supplying toner to a developing unit is known (see, for example, Japanese Patent Application Laid-open No. 2004-287404).
In Japanese Patent Application Laid-open No. 2004-287404, a toner container (a toner bottle), which is attached to a toner-container holding unit (a bottle holder) of an image forming apparatus in a replaceable manner, includes a container body and a cap portion. A spiral-shaped protrusion is formed on an inner circumferential surface of the container body, and the toner contained in the container body is conveyed toward an opening thereof through rotation of the container body. The cap portion communicates with the opening, and is held by the toner-container holding unit in a nonrotatable manner, i.e., the cap portion does not rotate with the container body. The toner discharged from the opening is discharged from a toner discharge opening provided in the cap portion, and is then supplied to the developing unit. The container body is rotated by the rotational force transmitted to a gear portion that is integrally provided on the container body.
Such toner container can reduce toner stain upon replacement of the toner container as compared with a toner container that has no cap portion and directly supplies toner from the opening of the container body to the developing unit such as the one disclosed in Japanese Patent Application Laid-open No. 2000-338758. Specifically, because the toner discharge opening is opened/closed in synchronization with a part of an attachment/detachment operation (rotating operation) of the toner container, such a problem that a user's hand becomes stained with toner by touching the toner discharge opening can be suppressed. Furthermore, because the toner discharge opening is directed downward in the vertical direction, after the toner in the toner container is used, the amount of toner remaining near the toner discharge opening can be small because of the drop by gravity. Therefore, the toner stain in the toner discharge opening upon replacement of the toner container is reduced.
When the toner container is to be attached to the toner-container holding unit, a user first opens a main-body cover (a stack portion) upwardly, so that the toner-container holding unit is exposed. Then, the toner container is placed on the toner-container holding unit from the upper side of the toner-container holding unit. Thereafter, the user holds a handle integrally provided on the cap portion, and rotates the cap portion (rotating operation). With the rotating operation, the position of the toner container with respect to the toner-container holding unit is finally fixed. Furthermore, with the rotation of the cap portion, a shutter resists the biasing force of a spring so that the toner discharge opening is opened downwardly.
Japanese Patent Application Laid-open No. 2004-161371 discloses a toner storage container that includes a bag container and a cap member. A toner discharge opening of the cap member is opened/closed in synchronization with a part of the attachment/detachment operation of the toner container (rotating operation of an opening/closing holder), for reducing toner stain (toner scatter) occurring upon the attachment/detachment operation.
Specifically, when the toner container is attached to the apparatus body, the opening/closing holder is first rotated around a hinge and the upper side of the opening/closing holder is exposed. Then, the toner container is set in the opening/closing holder. Thereafter, the opening/closing holder with the toner container set therein is rotated (rotating operation) around the hinge. With the rotating operation, the position of the toner storage container is finally fixed in the apparatus body. Furthermore, a plug member (a shutter member) is pushed by a nozzle in response to the rotation of the opening/closing holder to resist the biasing force of a spring, to thereby open the toner discharge opening sealed by a packing (a G-seal).
The toner container disclosed in Japanese Patent Application Laid-open No. 2004-287404 has less toner stain in the toner discharge opening compared with that disclosed in Japanese Patent Application Laid-open No. 2000-338758, and therefore, the effect of preventing such a problem that a user's hand becomes stained with toner by touching the toner discharge opening is expected. However, the toner container disclosed in Japanese Patent Application Laid-open No. 2004-287404 has disadvantages in terms of operability/workability upon its attachment/detachment (replacement).
A first disadvantage is that the attachment/detachment operation of the toner container to/from the toner-container holding unit includes a plurality of operations such as an operation of opening/closing the main-body cover, an operation of placing/removing the toner container onto/from the toner-container holding unit, and an operation of rotating the cap portion.
A second disadvantage is that it is difficult for a user to check that the operation is performed properly nearly until the completion of the attachment operation. Specifically, the user cannot feel certain that the operation is performed correctly at the point when the operation of opening the main-body cover and the operation of placing the toner container on the toner-container holding unit are completed. Thereafter, when rotating the cap portion to fix the position of the cap portion, if the user can have a feeling of a click of the cap portion, the user can feel certain that no erroneous operation is made.
A third disadvantage is that the upper side of the toner-container holding unit is restricted in terms of layout. Specifically, to place the toner container in the toner-container holding unit from the upper side, the main-body cover needs to be opened/closed in the vertical direction. Therefore, it is necessary to ensure space required for layout to open/close the main-body cover and place/remove the toner container. This reduces operability/workability in attachment/detachment of the toner container if a scanner (a document reader) or the like is provided above the toner-container holding unit.
Furthermore, in the toner container in Japanese Patent Application Laid-open No. 2004-287404, the container body is rotated by the rotational force transmitted to the gear portion that is integrally provided on the container body and is made of a material same as that of the container body. Specifically, the gear portion and the container body are often formed of polyethylene terephthalate (PET) or the like that is suitable for blow molding. Generally, such material does not have high mechanical strength. Thus, when the toner container has a large capacity (e.g., the toner container has a length of 500 mm or longer in a longitudinal direction) and contains a large amount of toner, a load imposed on the gear portion becomes large, which may result in wear or damage of the gear portion. Because the toner container with a worn or damaged gear portion cannot be recycled even if there is no defect except the gear portion, the efficiency of recycling the toner container is reduced.
In the toner container described in Japanese Patent Application Laid-open No. 2004-161371, because the plug member is pushed by the nozzle in synchronization with the opening operation of the opening/closing holder, to open the toner discharge opening sealed by the packing, the effect of reducing occurrence of toner stain can be expected. However, this toner container also has some disadvantages in terms of operability/workability upon its attachment/detachment.
A first disadvantage is that because the capacity of the toner container cannot be increased, the frequency of replacement of the toner container increases. Specifically, the toner container has a bag container for containing toner. The longitudinal direction of the bag container is vertical. Therefore, if the capacity of the bag container is to be increased, the height of the toner container needs to be increased. This increases the height of the opening/closing holder, thereby affecting the layout of the image forming apparatus in the height direction. Thus, the capacity of the toner container cannot be increased so much, and the toner container needs to be replaced more frequency than the toner container disclosed in Japanese Patent Application Laid-open No. 2004-287404 in which the longitudinal direction thereof is horizontal.
A second disadvantage is that it is difficult for a user to feel certain that no erroneous operation is made. Specifically, because the plug member opens/closes the toner discharge opening in synchronization with the opening/closing operation of the opening/closing holder, it is difficult for the user to feel if the toner discharge opening is actually opened or closed because the user does not touch the toner storage container during the operation.
Because the toner is a consumable, which greatly affects the image quality, it is preferable that information related to the toner (toner properties) contained in the toner container, which is frequently replaced, be shared between the image forming apparatus and a control unit. To accomplish that, an electronic component storing the toner information is installed in the toner container. However, for replacing the toner container, when a user attaches/detaches the toner container without paying attention to the electronic component, the toner container may hit the apparatus body and the electronic component may be damaged. Particularly, in a large-sized apparatus in which a toner container with large capacity (e.g., a toner container whose length in a longitudinal direction is 500 mm or longer) is provided, the workability for replacing the toner container is reduced due to the size and the weight of the toner container compared with a small-sized apparatus. Therefore, the possibility of damaging the electronic component is not negligible.